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This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

-moz-stack-sizing is an extended CSS property. Normally, a stack will change its size so that all of its child elements are completely visible. For example, moving a child of the stack far to the right will widen the stack so the child remains visible.

If you wish to prevent the stack from resizing automatically to accommodate its children, you can set -moz-stack-sizing to ignore on the child element. The property is set not on the stack itself, but on the stack's children. This lets you ignore certain children, but not others.

Note: In previous versions of Gecko it was possible to work around the problem by setting very large negative bottom and right margins on the stack element and equally large positive bottom and right margins on the children whose size you didn't want to ignore. (The problem does not affect children moved above or to the left of the stack.)

Initial valuestretch-to-fit
Applies toall elements
Computed valueas specified
Animation typediscrete
Canonical orderthe unique non-ambiguous order defined by the formal grammar


/* Keyword values */
-moz-stack-sizing: auto;
-moz-stack-sizing: ignore;

/* Global values */
-moz-stack-sizing: inherit;
-moz-stack-sizing: initial;
-moz-stack-sizing: unset;


The child will influence the stack's size.
The stack won't consider this child when calculating its size.

Formal syntax

ignore | stretch-to-fit


.mainsheet {
  -moz-stack-sizing: ignore;

See also

bug 346189

Document Tags and Contributors

 Last updated by: mfluehr,